Stream‐Stage Response Tests and Their Joint Interpretation with Pumping Tests

Abstract

Hydraulic head response to stream-stage variations can be used to explore the hydraulic properties of stream-aquifer systems at a relatively large scale. These stream-stage response tests, also called flooding tests, are typically interpreted using one- or two-dimensional models that assume flow perpendicular to the river. Therefore, they cannot be applied to systems that are both horizontally and vertically heterogeneous. In this work, we use the geostatistical inverse problem to jointly interpret data from stream-stage response and pumping tests. The latter tests provide flow data (which are needed to resolve aquifer diffusivity into transmissivity and storage coefficient) and may supply supplementary small-scale information. Here, we summarize the methodology for the design, execution, and joint numerical interpretation of these tests. Application to the Aznalcóllar case study allows us to demonstrate that the proposed methodology may help in responding to questions such as the continuity of aquitards, the role and continuity of highly permeable paleochannels, or the time evolution of stream-aquifer interaction. These results expand the applicability and scope of stream-stage response tests.

In-situ remediation of acid mine drainage using a permeable reactive barrier in Aznalcóllar (Sw Spain)

“…It also shows the variability of groundwater head attributable to seasonal conditions and/or sporadic rainfall events, with raises following heavy and sustained rainfalls during the period 5-7 months and after approximately 17 and 29 months after the PRB installation. The rainfall events eroded the stream bed and enhanced the hydraulic connection of the Agrio river to the lower gravel layer [29], which in turn led to increases of groundwater flow. This must be borne in mind in interpreting the water quality in the sections further below.…”

Groundwater contamination evolution in the Guadiamar and Agrio aquifers after the Aznalcóllar spill: assessment and environmental implications

“…In the Agrio River zone, very coarse-sized grain prevails, with hydraulic conductivities between 500 and 700 m/day and storage coefficient between 0.08 and 0.23 . In this zone, Rotting et al (2006) distinguish two permeable layers separated by silts, which behave as aquitard.…”

Calibration of spatial aquitard distribution using hydraulic head changes and regularisation

“…A method is developed which allows a spatial aquitard characterisation using operational data and hydraulic heads. Rötting et al (2006) carried out inversion of cross hole pumping tests to determine simultaneously aquifer parameters and the hydraulic connection to an adjacent river. We propose an alternative approach of characterising the aquifer properties by using operational data from well fields instead of data from defined tests.…”